Communicable diseases- public health

Question 1

The 3 key domains of public health practice

Answer 1

1. Health improvement
2. Improving services
3. Health protection

Question 2

Goal of public health

Answer 2

“Protection of people from infectious diseases and preventing harm from non-communicable diseases and preventing harm from non-communicable environmental hazards involving chemicals, poisons or radiation.”

Question 3

Areas of public health concern for the UK:

Answer 3

1. Healthcare acquired infections
2. Antimicrobial resistance
3. Sexually transmitted infections- overall rates falling but gonorroea increasing
4. Emerging infections- ebola, zika, COVID-29, polio

Question 4

Chain of infection (6)

Answer 4

1. Portals of entry- e.g., mucous membrane
2. Susceptible host- Immune deficient
3. Infectious agent- e.g, Bacteria
4. Reservoirs- people, water
5. Portals of exit- blood, secretions
6. Modes of transmission- physical contact

Question 5

Incubation period defintition

Answer 5

time period between initial contact with an infectious agent and the appearance of the first sign or symptom of disease

Question 6

Infectious period (period of communicability)

Answer 6

the time during which an infectious agent may be transferred directly or indirectly from an infected person to another person etc.”

Question 7

Transmissibilty of infection can be described with which values

Answer 7

Reproduction number

Basic reproduction number R0

Effective reproduction numer R

Question 8

Definition of reproduction number

Answer 8

the average number of new people infected by each infectious case

Question 9

Bsic reproduction number R0

Answer 9

the mean number of secondary cases a typical single infected case will cause in a population with no immunity to the disease, in the absence of interventions to control the infection.

Question 10

Effective reproduction number - R

Answer 10

The number of secondary infections produced by a typical infective case

Takes into account the fact that some poeple are already immune, because of previous infection or vaccination

Question 11

Definition of sporadic disease occurance

Answer 11

irregular pattern, occasionally cases at irregular intervals

e.g, typhoid

Question 12

Endemic disease occurance

Answer 12

persistent, low or moderate level of disease

e.g., malaria, Tb

Question 13

Hyper endemic

Answer 13

A higher persistent level

e.g., hep B

Question 14

Epidemuc

Answer 14

occurance exceeds the expected level for a givem time period

e.g., measles outbreak

Question 15

pandemic

Answer 15

epidemic spreadinf over several countries or continents

Question 16

Suspected case definition

Answer 16

any febrile (showing symptoms of fever) illness accompanied by a rash

Question 17

Probable case definition

Answer 17

A case that meets the clinical case definition, has non-contributory or no serologic or virologic testing, and is not epidemiologically linked to a confirmed case

Question 18

Principles of communicable diseases control

Answer 18

1. Control the source
2. Interrupt transmission- vector control, needle exchange, hand washing
3. Protect the suceptible population by immunisation or chemoprophylaxis

Question 19

Management of suspected outbreak (typhoid)

Answer 19

• Check antibiotic resistance of the organism isolated from the culture
• Ensure cases are isolated
• Observe enteric precautions and give personal hygiene advice
• Obtain food and travel history
• Investigate household and other close contacts with a faecel specimen for culture- those who are positive should be treated as cases

Question 20

Is this an outbreak?

Answer 20

2 or more cases arising within the same 48 hour window OR 3 or more within the same 72 hour window which meet the same clinical case definition where an epidemiological link can be established.

Question 21

Principles of outbreak management

Answer 21

Immediate control measures

Incident/ outbreak control team

Case finding

Data collection and analysis

Hypothesis generation and testing

Further control measures